Portable handheld work apparatus having an internal combustion engine

摘要

In an internal combustion engine (2) of a portable handheld work apparatus, the cylinder (3) is provided with cooling ribs (4, 4′). A cooling airflow is generated by the fan wheel (13) and is guided over the cooling ribs. A carburetor (9) is temperaturized as required by the heated cooling air. A control of the cooling airflow to the carburetor (9) takes place in that an opening (11), which passes the heated cooling air, is selectively closed or opened via a closure element (12). In order to obtain improved cooling of the cylinder during summer operation as well as during winter operation, the closure element (12) is provided with at least one air guide wall which extends essentially transversely to the cooling airflow and causes this cooling air to be partially backed up and deflected.

主权项

1. A portable handheld work apparatus comprising:
an internal combustion engine having a cylinder provided with cooling ribs; a carburetor having a carburetor housing and being operatively connected to said engine; a fan wheel for generating a cooling airflow passing over said cooling ribs causing said cooling airflow to become a heated cooling airflow; a housing having an engine compartment for accommodating said engine therein and a carburetor compartment for accommodating said carburetor therein and having an intermediate wall separating said compartments from each other; an opening passing said heated cooling airflow to said carburetor for temperaturizing said carburetor as may be needed; a closure element for selectively opening or closing said opening for controlling the heated cooling airflow to said carburetor; said opening being disposed in said intermediate wall; said closure element having an air guide wall extending substantially transversely to said heated cooling airflow so as to cause said heated cooling airflow to be at least in part backed up and deflected; and, said closure element being configured to be in a selectable position so as to cause said heated cooling airflow to be split into a first component of heated cooling airflow configured to flow into said carburetor compartment to there flow about said carburetor housing so as to warm said carburetor housing from the outside thereof and a second component of heated cooling airflow configured to flow toward said cooling ribs.